BMC Genomics最新文献

Background: Myopia development is commonly assessed by an increase in axial length, which may lead to high myopia and visual impairment. This study aims to identify potential biomarkers and signaling pathways in the sclera during experimental axial elongation.

Methods: A myopia guinea pig model was established using male guinea pigs aged 2-3 weeks, which underwent bilateral lens-induced myopization (LIM) (study group) or were left untreated (control group). An integrated analysis of transcriptomic and proteomic was performed to identify differentially expressed genes (DEGs) in the sclera. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to explore the DEGs related signaling pathways. Promising candidate markers were further tested by Western blot analysis. Transmission electron microscopy was used to assess scleral fiber changes in myopic guinea pigs.

Results: During the study period, axial elongation was significantly greater in the study group (0.59 ± 0.05 mm vs. 0.47 ± 0.02 mm; P < 0.001), accompanied by a reduction in the thickness of the retina (121.9 ± 2.50 μm vs. 134.6 ± 0.48 μm; P < 0.001), choroid (38 ± 1.0 μm vs. 50 ± 0.8 μm; P < 0.001), and sclera (100.8 ± 2.78 μm vs. 155.6 ± 4.78 μm; P < 0.001). Integrated transcriptomic and proteomic analyses identified 34 upregulated genes, with significant activation and enrichment of the circadian rhythm pathway. Among the top enriched pathways, key differentially expressed genes included retinoid-related orphan receptors RORα and RORβ, which are recognized as critical signals modulating the scleral hypoxia response. Western blot analysis confirmed upregulation of RORα, RORβ, melatonin receptor type 1 (MT1), and HIF-1α in the sclera, while melatonin receptor type 2 (MT2) expression remained unchanged between the groups. Transmission electron microscopy revealed a significantly higher proportion of thin collagen fibers compared to thick fibers in the LIM group (P < 0.05).

Conclusions: Axial elongation-related remodeling of scleral collagen is closely linked to circadian rhythm and hypoxia pathways, with RORα, RORβ, melatonin receptors, and HIF-1α identified as potential key regulators. Additionally, scleral fiber size decreases progressively with scleral remodeling in myopia development.

Dairy goats, a livestock species with a long history of milk production, are essential for the economic advancement of nations, particularly in regions experiencing growth. In this study, we gathered whole-genome resequencing data of 58 goats, including 34 dairy goats and 24 wild goats (Bezoar), to explore the selection signatures linked to milk production traits using ROH (Runs of homozygosity), CLR (composite likelihood ratio), Fst (Fixation index), XP-EHH (Ex-tended haplotype homozygosity across populations) and XP-CLR(Cross-population composite likelihood ratio test) methods. Analysis of five tests of selection signatures for dairy goats revealed a total of 210 genes, with 24 genes consistently identified in at least two approaches. These genes are associated with milk fat, milk protein, and fat yield. Gene enrichment analysis highlighted important GO and KEGG pathways related to milk production, such as the "acyl-CoA metabolic process", "glycerolipid biosynthetic process", "cellular response to fatty ac-id", "hormone metabolic process", "Galactose metabolism". Additionally, genes linked to repro-duction, immune response, and environmental adaptation were identified in dairy goats. The findings from our study offer profound understanding into the critical economic features of dairy goats and offer practical guidance for the improvement and development of crossbreeding initiatives across different dairy goat breeds.

Gaeumannomyces tritici is responsible for take-all disease, one of the most important wheat root threats worldwide. High-quality annotated genome resources are sorely lacking for this pathogen, as well as for the closely related antagonist and potential wheat take-all biocontrol agent, G. hyphopodioides. As such, we know very little about the genetic basis of the interactions in this host-pathogen-antagonist system. Using PacBio HiFi sequencing technology we have generated nine near-complete assemblies, including two different virulence lineages for G. tritici and the first assemblies for G. hyphopodioides and G. avenae (oat take-all). Genomic signatures support the presence of two distinct virulence lineages in G. tritici (types A and B), with A strains potentially employing a mechanism to prevent gene copy-number expansions. The CAZyme repertoire was highly conserved across Gaeumannomyces, while candidate secreted effector proteins and biosynthetic gene clusters showed more variability and may distinguish pathogenic and non-pathogenic lineages. A transition from self-sterility (heterothallism) to self-fertility (homothallism) may also be a key innovation implicated in lifestyle. We did not find evidence for transposable element and effector gene compartmentalisation in the genus, however the presence of Starship giant transposable elements may contribute to genomic plasticity in the genus. Our results depict Gaeumannomyces as an ideal system to explore interactions within the rhizosphere, the nuances of intraspecific virulence, interspecific antagonism, and fungal lifestyle evolution. The foundational genomic resources provided here will enable the development of diagnostics and surveillance of understudied but agriculturally important fungal pathogens.

Background: To solve the problem of an insufficient supply of dairy products in Tibet, work has been carried out to improve native dairy cattle and introduce purebred dairy cattle from low-altitude areas. The harsh environment of the plateau not only severely limits the production performance of high-yielding dairy cattle, such as Holstein and Jersey cattle, but also challenges their survival. The population structure and plateau adaptation mechanism of plateau dairy cattle are rarely reported. In this study, key genes and pathways affecting plateau purebred and crossbred dairy cattle were explored using genetic chip information.

Results: The results showed that the genetic diversity of the Tibet dairy cattle population was higher than that of the native cattle and plains dairy cattle. Purebred Holstein and Jersey cattle in Tibet were genetically closer to dairy cattle in the plains, and crossbred dairy cattle were admixed with more Tibet cattle and Apaijiza cattle. Based on the fixation index (F_ST), integrated haplotype score (iHS), and cross-population extend haplotype homozygosity (XP-EHH) approaches, 60 and 40 genes were identified in plateau Holstein and Jersey cattle, respectively. A total of 78 and 70 genes were identified in crossbred cattle compared to Holstein and Tibet cattle respectively. These genes are related to cardiac health and development, neuronal development and function, angiogenesis and hematopoietic, pigmentation, growth and development, and immune response.

Conclusions: Our results provide a glimpse into diverse selection signatures in plateau dairy cattle, which can be used to enhance our understanding of the genomic basis of plateau adaptation in dairy cattle. These results support further research on breeding strategies such as marker-assisted selection and gene editing in plateau dairy cattle populations.

Background: Cold stress significantly challenges cotton growth and productivity, yet the genetic and molecular mechanisms underlying cold tolerance remain poorly understood.

Results: We employed RNA-seq and iterative weighted gene co-expression network analysis (WGCNA) to investigate gene and transposable element (TE) expression changes at six cold stress time points (0 h, 2 h, 4 h, 6 h, 12 h, 24 h). Thousands of differentially expressed genes (DEGs) were identified, exhibiting time-specific patterns that highlight a phase-dependent transcriptional response. While the A and D subgenomes contributed comparably to DEG numbers, numerous homeologous gene pairs showed differential expression, indicating regulatory divergence. Iterative WGCNA uncovered 125 gene co-expression modules, with some enriched in specific chromosomes or chromosomal regions, suggesting localized regulatory hotspots for cold stress response. Notably, transcription factors, including MYB73, ERF017, MYB30, and OBP1, emerged as central regulators within these modules. Analysis of 11 plant hormone-related genes revealed dynamic expression, with ethylene (ETH) and cytokinins (CK) playing significant roles in stress-responsive pathways. Furthermore, we documented over 15,000 expressed TEs, with differentially expressed TEs forming five distinct clusters. TE families, such as LTR/Copia, demonstrated significant enrichment in these expression clusters, suggesting their potential role as modulators of gene expression under cold stress.

Conclusions: These findings provide valuable insights into the complex regulatory networks underlying cold stress response in cotton, highlighting key molecular components involved in cold stress regulation. This study provides potential genetic targets for breeding strategies aimed at enhancing cold tolerance in cotton.

Sweet sorghum (Sorghum bicolor Moench) seedling emergence and growth are significantly impeded by physical soil crusts (PSCs) in saline-alkaline soils. Abscisic acid (ABA) is a potent seed priming agent known for modulating plant physiological and metabolic responses under salinity stress. However, the influence of ABA priming on seedling emergence in PSCs remains unclear. This study conducted both pot and field experiment to examine the effects of ABA priming on enhancing seedling emergence under PSC conditions. ABA priming altered the balance of at least 24 endogenous phytohormones, including abscisic acid, jasmonic acid, gibberellins, ethylene, auxins, and cytokinins. Additionally, it reprogrammed starch and sucrose metabolism, resulting in the differential expression of genes encoding key enzymes such as AMY, BAM, and INV, which are crucial for converting complex sugars into readily available energy sources, thereby supporting seedling growth. Furthermore, 52 differentially expressed metabolites (DEMs) of flavonoids were identified in germinating seedlings, including 15 anthocyanins, 3 flavones, 7 flavonols, 6 isoflavones, 7 flavanones, and 14 other flavonoids. Genetic and metabolic co-expression network analysis, along with flavonoid biosynthesis pathway exploration, revealed that the biosynthesis of 17 key DEMs-including liquiritigenin, apigenin, kaempferide, syringetin, phloretin, formononetin, dihydrokaempferol, and xanthohumol-was regulated by 10 differentially expressed genes (DEGs) associated with flavonoid biosynthesis. These DEGs encoded 7 enzymes critical for this pathway, including chalcone synthase, shikimate O-hydroxycinnamoyltransferase, bifunctional dihydroflavonol 4-reductase, naringenin 7-O-methyltransferase, and anthocyanidin reductase. This regulation, along with reduced levels of superoxide anion (O₂^-) and malondialdehyde and increased antioxidant enzyme activities, suggested that flavonoids played a vital role in mitigating oxidative stress. These findings demonstrate that ABA priming can effectively enhance sweet sorghum seedling emergence in PSCs by accelerating emergence and boosting stress resistance.

Background: Oocyte maturation is a critical process responsible for supporting preimplantation embryo development and full development to term. Understanding oocyte gene expression is relevant given the unique molecular mechanism present in this gamete. Comparative transcriptome analysis across species offers a powerful approach to uncover conserved and species-specific genes involved in the molecular regulation of oocyte maturation throughout evolution.

Results: Transcriptome analysis identified 4,625, 3,824, 4,972 differentially expressed genes (DEGs) between the germinal vesicle (GV) and metaphase II (MII) stage in human, porcine and mouse oocytes respectively. These DEGs showed dynamic changes associated with oocyte maturation. Functional enrichment analysis revealed that the DEGs in all three species were mainly involved in DNA replication, cell cycle and redox regulation. Comparative transcriptome analysis identified 551 conserved DEGs in the three species with significant enrichment in mitochondria and mitochondrial intima.

Conclusions: This study provides a systematic comparative analysis of oocyte meiotic maturation in humans, pigs and mice identifying both conserved and species-specific patterns during oocyte meiosis. Our findings also implied that the selection of oocyte expressed genes among these three species could form a basis for further exploring their functional roles in human oocyte maturation.

The Chinese giant salamander (CGS), Andrias davidianus, the largest living amphibian, is of significant conservation importance for its wild populations and serves as a valuable economic species in aquaculture. Given that male CGS are larger than female, understanding the mechanisms behind gonadal differentiation and development is critical for optimizing production in aquaculture. This study conducted small RNA-seq on male and female gonads during two key differentiation windows in CGS. PCA analysis revealed distinct clustering within groups and clear differentiation between groups. A total of 374 miRNAs were identified, including 162 known and 212 novel miRNAs. Differential expression and enrichment analysis across the two time points identified nine sex-biased miRNAs involved in CGS gonadal differentiation, including let-7b-3p, miR-3529-3p, miR-34c-5p, miR-10-5p, miR-7-5p, and four novel miRNAs, and network of these nine sex-biased miRNAs with their target genes were constructed. Furthermore, our findings suggest that male and female gonadal development processes are likely regulated by distinct miRNAs. This study provides a comprehensive analysis of sex-biased and gonadal development related miRNAs in CGS, offering a theoretical foundation for enhancing CGS aquaculture productivity through targeted sex ratio management.

Background: Genome-wide association studies (GWAS) are rapidly advancing due to the improved resolution and completeness provided by Telomere-to-Telomere (T2T) and pangenome assemblies. While recent advancements in GWAS methods have primarily focused on identifying genetic variants associated with discrete phenotypes, approaches for quantitative traits (QTs) remain underdeveloped. This has often led to significant variants being overlooked due to biases from genotype multicollinearity and strict p-value thresholds.

Results: We propose an enhanced ensemble learning approach for QT analysis that integrates regularized variant selection with machine learning-based association methods, validated through comprehensive biological enrichment analysis. We benchmarked four widely recognized single nucleotide polymorphism (SNP) feature selection methods-least absolute shrinkage and selection operator, ridge regression, elastic-net, and mutual information-alongside four association methods: linear regression, random forest, support vector regression (SVR), and XGBoost. Our approach is evaluated on simulated datasets and validated using a subset of the PennCATH real dataset, including imputed versions, focusing on low-density lipoprotein (LDL)-cholesterol levels as a QT. The combination of elastic-net with SVR outperformed other methods across all datasets. Functional annotation of top 100 SNPs identified through this superior ensemble method revealed their expression in tissues involved in LDL cholesterol regulation. We also confirmed the involvement of six known genes (APOB, TRAPPC9, RAB2A, CCL24, FCHO2, and EEPD1) in cholesterol-related pathways and identified potential drug targets, including APOB, PTK2B, and PTPN12.

Conclusions: In conclusion, our ensemble learning approach effectively identifies variants associated with QTs, and we expect its performance to improve further with the integration of T2T and pangenome references in future GWAS.

Background: Changing ocean temperatures are already causing declines in populations of marine organisms. Predicting the capacity of organisms to adjust to the pressures posed by climate change is a topic of much current research effort, particularly for species we farm or harvest. To explore one measure of phenotypic plasticity, the physiological compensations in response to heat stress as might be experienced in a marine heatwave, we exposed Yellowtail Kingfish (Seriola lalandi) to sublethal heat stress, and used the transcriptome in gill and muscle, benchmarked against heat shock proteins and oxidative stress indicators, to characterise the acute heat stress response (6 h after the initiation of stress), and the physiological compensation to that response (24 and 72 h after the initiation of stress).

Results: The heat stress experiments induced elevations in heat shock proteins, as measured in blood, demonstrating the sublethal stress level. The initial response (6 h) to heat stress included the expected cellular stress response. Exposure of 24 h or more led to altered transcriptomic patterns for protein degradation, membrane transporters, and primary metabolism. In the muscle, numerous transcripts with mitochondrial function had altered abundance. There was a profound change to the regulation of transcription, as well as numerous transcripts with differential exon usage, suggesting that this may be a mechanism for conferring physiological resilience to heat stress.

Conclusions: These results demonstrate the processes involved in acclimation to heat stress in this species, and the utility of using the transcriptome to assess plasticity. It also showed that differential exon usage may be an important mechanism for conferring plasticity. Future work should investigate the role of genome regulation, and alternative splicing in particular, on conferring resilience to temperature changes.